Liquid effluents resulting from the draining of culture soils are subject to regulations aiming at reducing the number of pollutants contained in these effluents.
Among these pollutants, nitrates are more particularly targeted.
Within the scope of hydroponic tomato cultures in green houses for example, the liquid effluents from the draining waters may contain a nitrate concentration ranging up to 3 g/L for a maximum flow rate of 31 m3/day/hectare.
Now, discharging these waters is harmful for the environment, the maximum nitrate concentration for the environment may be estimated to be 50 mg/L.
A biological treatment of these effluents is possible but has two major drawbacks, i.e. the presence of organic compounds not easily biodegradable in the effluents, the requirement of a significant addition of methanol as well as the presence of microorganisms which is not very desirable in proximity to the culture location.
In this context, the invention is directed to a method for treating a liquid medium loaded with nitrates with which the nitrate concentration may be reduced and not requiring the use of polluting organic species, which may be detrimental to the environment. The invention also lies in a device with which a liquid medium loaded with nitrates may be treated and in the possible applications of the method of the invention.
For this purpose, the invention relates to a method for mixed chemical electrochemical treatment of a liquid medium loaded with nitrates.